Power module packages typically use wire bonding which is a source of high resistance and noise. As the number of connections using wire bonding has increased significantly, problems of increased resistance, signal delays and signal interference has limited the further efficiency and density of future power modules. MLP and flip chip technologies have resulted in improved packaging designs. U.S. Pat. No. 6,507,120 B2, issued Jan. 14, 2003, inventors Lo et al., and U.S. Pat. No. 6,867,072 B1, issued Mar. 15, 2005, inventors Shiu et al., disclose flip chip and molding techniques which are improvements over traditional wire bonding techniques. U.S. Pat. No. 6,891,256 B2, issued May 10, 2005, inventors Joshi et al., discloses a thin, thermally enhanced flip chip in a leaded molded package which has been suitable for the applications for which it was intended. The package disclosed, however, has certain drawbacks, viz., the leaded molded package occupies more space than a molded leadless package, the heat sink is designed only for a leaded package and not a leadless package, and the method of heat sink attachment is not defined clearly (only that a clip is coupled to the exposed drain, and that paste dispense or printing may be used for such clip attachment).
With a current MLP package design utilizing a wire bond technique, performance, when a power device is housed, will be noncompetitive in terms of electrical and thermal characteristics. The generation of an MLP with clip bonding on the source and wirebond on the gate is costly and tedious and requires a longer processing flow (die attach, clip attach, and wirebond).
There is thus a need for a flip chip power device MLP type of package that is competitive in terms of electrical and thermal characteristics, that uses a simpler, less costly and tedious process to produce the package, and that efficiently addresses cooling problems.